Signal Peptide of Potato PinII Enhances the Expression of Cry1Ac in Transgenic Tobacco

Insect-resistant plants have been developed throughexpression of insecticidal proteins from Bacillusthuringiensis (Bt) in the early 1980s [1,2]. However, forcontrol of insect pests, it is necessary to increase theexpression of Bt protein overall or in specific plant tissues.To increase the expression level, synthetic Bt genes havebeen developed and used to produce transgenic plants[2–5]. A number of approaches have been taken to increasethe expression level of foreign proteins in transgeni…     

应用荧光原位杂交技术检测人βE珠蛋白基因在转基因小鼠染色体上的整合状态

为将荧光原位杂交技术应用于基因定位研究中,探讨一种能有效地检测转基因动物染色体上外源基因整合状态的实验方法,对小鼠腹腔注射秋水仙素后,取转基因小鼠骨髓制备中期染色体,将传统的FISH方法加以改进,检测外源基因在转基因小鼠染色体上的整合状态.检测结果表明,外源人βE珠蛋白基因已稳定地整合于小鼠染色体上.FISH能直观地反映外源基因在转基因动物染色体上的整合状态,该方法可对转基因动物及基因转移研究中的外源基因整合后进行染色体定位检测。 Abstract:To determine the integration site of human βE globin gene in the chromosomes of transgenic mice, transgenic mice carrying human βE globin gene were injected intraperitoneally with colchicines, then, bone marrow cells wereisolated and metaphase chromosomes were prepared, the traditional FISH method was improved to detect the integration site of humanβE globin gene in transgenic mice when combined with G-banding. Human t3E globin gene can bedetected in different position of different chromosomes in transgenic mice and FISH signals showed that two mice were heterozygous of human 13E globin gene and one was homozygous. Human t3E globin gene was integrated into thechromosomes of transgenic mice in a random pattern and the results demonstrated that FISH can be used to investigate the integration site of foreign genes in transgenic mice.     

The interaction of laminin and its membrane receptor on mouse macrophage membrane studied by STM and FRAP

The variation of membrane surface and lateral diffusion of membrane protein was studied after the interaction of laminin with its membrane receptor in mouse macrophages. A pattern of membrane surface which showed smaller and bigger peaks was obtained by scanning tunneling microscope(STM), looking like the domains of lipid groups and proteins in the model of fluid mosaic biomembrane. Some even more higher and wider peaks projected out from the membrane surface in STM image after the interacting of laminin with membrane receptor were, probably, the complexes of laminin and membrane receptor. Furthermore, the decreased lateral diffusion coefficient value (D) was obtained by fluorescence recovery after photobleaching (FRAP) after the laminin was reacted with membrane receptor. This phenomenon provides an evidence that the complexes of laminin and its membrane receptor were located on the membrane of macrophages. So we could consider that the laminin is combined with membrane receptor leading to the variation in the properties of membrane surface.     

Different quasispecies with great mutations hide in the same subgroup J field strain of avian leukosis virus

Blood samples were collected from a local strain of chickens associated with serious tumor cases in Shandong Province.The samples were inoculated into chicken embryo fibroblast and DF-1 cells for virus isolation and identification,respectively.The inoculated cells were screened for three common chicken tumor viruses.Nine strains of avian leukosis virus subgroup J(ALV-J) were identified,and were designated LY1201‐LY1209.The env gene from the LY1201 strain was amplified and cloned.All nine resultant env clones(clones 01-09) were sequenced,and the gp85 and gp37 amino acid regions were subjected to homology analysis.Clones 01 and 03 had 10 amino acid deletions in the gp85 region compared to the other seven clones,suggesting that at least two quasispecies with obvious mutations coexist in the same field strain.Among these nine clones,three had identical gp85 and gp37 sequences,and were recognized as the dominant LY1201 quasispecies.The amino acid sequence homology of gp37 and gp85 among the nine clones was 98.5%-100.0% and 96.6%-100.0% respectively,suggesting that the gp85 region of the env gene can better display the quasispecies diversity of ALV-J than gp37.     

Highly efficient uptake of ultrafine mesoporous silica nanoparticles with excellent biocompatibility by Liriodendron hybrid suspension cells

The characteristics of the interactions co-cultures of ultrafine mesoporous silica nanoparticles (MSNs) and the Liriodendron hybrid suspension cells were systematically investigated using laser scanning confocal microscope (LSCM) and scanning electron microscopy (SEM). Using fluorescein isothiocyanate (FITC) labeling, the LSCM observations demonstrated that MSNs (size, 5-15nm) with attached FITC molecules efficiently penetrated walled plant cells through endocytic pathways, but free FITC could not enter the intact plant cells. The SEM measurements indicated that MSNs readily aggregated on the surface of intact plant cells, and also directly confirmed that MSNs could enter intact plant cells; this was achieved by determining the amount of silicon present. After 24 h of incubation with 1.0mg mL-1 of MSNs, the viability of the plant cells was analyzed using fluorescein diacetate staining; the results showed that these cells retained high viability, and no cell death was observed. Interestingly, after the incubation with MSNs, the Liriodendron hybrid suspension cells retained the capability for plant regeneration via somatic embryogenesis. Our results indicate that ultrafine MSNs hold considerable potential as nano-carriers of extracellular molecules, and can be used to investigate in vitro gene-delivery in plant cells.     

Nelumbonaceae:Systematic position and species diversification revealed by the complete chloroplast genome

<正>Nelumbonaceae is a morphologically unique family of angiosperms and was traditionally placed in Nymphaeales;more recently,it was placed in Proteales based on molecular data,or in an order of its own,Nelumbonales. To determine the systematic position of the family and to date the divergence time of the family and the divergence time of its two intercontinentally disjunct species,we sequenced the entire chloroplast genome of Nelumbo lutea and most of the chloroplast genes of,N.nucifera.We carried out phylogenetic and molecular dating analyses of the two species and representatives of 47 other plant families,representing the major lineages of angiosperms, using 83 plastid genes.The N.lutea genome was 163 510 bp long,with a total of 130 coding genes and an overall GC content of 38%.No significant structural differences among the genomes of N.lutea,Nymphaea alba, and Platanus occidentalis were observed.The phylogenetic relationships based on the 83 plastid genes revealed a close relationship between Nelumbonaceae and Platanaceae.The divergence times were estimated to be 109 Ma between the two families and 1.5 Ma between the two Nelumbo species.The estimated time was only slightly longer than the age of known Nelumbo fossils,suggesting morphological stasis within Nelumbonaceae.We conclude that Nelumbonaceae holds a position in or close to Proteales.We further conclude that the two species of Nelumbo diverged recently from a common ancestor and do not represent ancient relicts on different continents.     

DNA sequence comparative analysis of the 3pter-p26 region of human genome

Most proterminal regions of human chromosomes are GC-rich and gene-rich. Chromosome 3p is an exception. Its proterminal region is GC-poor, and likely to lose heterozy-gosity, thus causing a number of fatal diseases. Except one gap left in the telomeric position, the proterminal region of human chromosome 3p has been completely sequenced. The detailed sequence analysis showed: (i) the GC content of this region was 38.5%, being the lowest among all the human proterminal regions; (ii) this region contained 20 known genes and 22 predicted genes, with an average gene size of 97.5 kb. The previously mapped gene Cntn3 was not found in this region, but instead located in the 74 Mb position of human chromosome 3p; (iii) the interspersed repeats of this region were more active than the average level of the whole human genome, especially (TA)n, the content of which was twice the genome average; (iv) this region had a conserved synteny extending from 104.1 Mb to 112.4 Mb on the mouse chromosome 6, which was 8% larger in size, not in accordance with the whole genome comparison, probably because the 3pter-p26 region was more likely to lose neocleitides and its mouse synteny had more active interspersed repeats.     

Construction, detection and microarray analysis on theShigella flexneri 2asitC mutant

Bacteria of Shigella spp. are commonly called Ba-cillus dysenteriae. The bacillary dysentery caused byShigella is one of the most serious infectious diseasesthroughout the world, especially in the developing countries. The completion of whole genome sequenc-ing of Shigella flexneri 2a strain 301 (brieflySf301)[1] offered a large amount of information andinvaluable clues for its functional genomic research.Microbial functional genomic research aims at deeplyinterpreting the function of genes …     

The symptom difference induced by Tobacco mosaic virus and Tomato mosaic virus in tobacco plants containing the N gene is determined by movement protein gene

Tobacco mosaic virus (TMV) and Tomato mosaicvirus (ToMV) are members of the genus Tobamoviruswith a world-wide distribution, and cause severe dis-eases on many economically important crops. TMVand ToMV have very close relationship and both havessRNA genome with a length of about 6400 nucleo-tides, encoding at least three nonstructural proteinsand a 17.6 kD coat protein (CP). Both 126 kD and 183kD proteins function as components of replicase, andthe 30 kD protein is involved in viral ce…     

武夷山烟腹毛脚燕孵卵节律的初步研究

2007年4～5月在江西武夷山国家级自然保护区黄岗山顶峰周围选取烟腹毛脚燕5个巢,利用温度记录仪对其孵卵节律进行了研究.研究表明:烟腹毛脚燕为双亲孵卵,窝卵数与孵化期无相关性(r=0.419, P=0.482);各巢亲鸟日活动期均在800 min以上,坐巢率与日环境温度无关,但随着进入孵卵天数的增加而逐渐增加,离巢次数随之减少.